1. Technical Field
An improved valve assembly for use in a pressurized dispenser is disclosed. The valve member provides faster product and/or propellant filling. The disclosed valve assembly may include a valve housing and a blocking member disposed within the valve housing, wherein the valve housing includes at least one transverse primary opening and at least one transverse secondary opening thereon. The blocking member is movable from a filling position, in which the product and/or propellant may be charged into the dispenser through both the primary and secondary openings, to a dispensing position, in which the product and/or propellant may be dispensed from the dispenser only through the primary opening and not through the secondary opening.
2. Description of the Related Art
Pressurized dispensers have been commonly used to store and dispense personal, household, industrial, and medical products, and provide a low cost, easy to use method of dispensing products that are best used as an airborne mist or as a thin coating on surfaces. The pressurized dispensers generally include a sealed container closed at one end and having a dispensing valve assembly on the other end for controlled filling or dispensing of the products contained therein. The products to be dispensed include a wide variety of liquid products, such as cleansers, insecticides, paints, deodorants, disinfectants, air fresheners, etc. A propellant may be used to discharge the liquid product from the dispenser. The propellant is pressurized and provides a force to expel the liquid product from the dispenser through the dispensing valve assembly when a user actuates the pressurized dispenser by pressing an actuator button or trigger.
In general, the pressurized dispensers may be single-chambered, in which the propellant and product are mix with each other, or multi-chambered, in which the propellant and product are separated. In a single-chambered pressurized dispenser, the dispenser is charged with the liquid product and propellant through the valve assembly to a pressure approximately equal to or slightly greater than the vapor pressure of the propellant, thereby allowing some of the propellant to be dissolved or emulsified in the liquid product. The remainder of the propellant remains in the vapor phase and fills the head space of the dispenser.
During dispensing, the valve assembly is depressed to expose a dispensing passageway therein and cause both the product and the propellant to be dispensed from the dispenser. As the product is dispensed, the pressure in the dispenser remains approximately constant as liquid propellant may move from the liquid phase into the vapor phase thereby replenishing discharged propellant vapor. Single-chambered pressurized dispensers have the benefit of simpler design and lower production cost.
Multi-chambered pressurized dispensers, on the other hand, may have a variety of configurations, including bag-on-valve, bag-on-can or piston designs. In general, the container of the dispenser is divided by a barrier member into product and propellant chambers. The barrier member may be a bag sealed to the valve assembly, a bag sealed to the container wall, or a piston member slidably disposed within the container. Generally, the product is charged into the product chamber through the valve assembly, whereas the propellant is charged into the propellant chamber through either the valve assembly or a charging orifice provided on the container wall.
Because the valve assembly provides fluid passageways during the filling and dispensing operations of the pressurized dispenser, a valve assembly specifically designed to accommodate optimum efficiency of both operations is highly desirable. For example, increasing product flow through the valve assembly during the filling operation expedites the manufacturing process of the pressurized dispenser. However, the increased product flow may adversely affect the spray characteristics of the dispenser. Thus, there is a need for a valve assembly that provides an increase flow rate during product filling while retaining a regular flow rate during product dispensing.
Valve assemblies that accommodate both product filling and dispensing by modifying flow paths are well known in the art. For example, a valve assembly adapted for fast pressure filling and metered dispensing of a product may include a valve body having a top and a bottom, a valve stem inserted through the top of the valve body, and a piston-like member disposed within and connected to the bottom of the valve body. The valve stem is connected to the piston-like member through a spring. The bottom of the valve body includes a center opening and an annular opening formed between a cylindrical flange of the piston-like member and the interior cylindrical surface of the valve body. In product dispensing, the product is dispensed through the center opening while the annular opening is closed by a biasing force of the flange against the interior surface of the valve body. In pressure filling, however, the valve stem is depressed thereby blocking the center opening. The pressure of the product then flows through the annular opening against the biasing force of the flange.
In another example, a valve assembly includes a valve body having a bottom opening, a valve stem inserted through the top of the valve body, and a spring connecting the bottom of the valve stem to the middle portion of the valve body. The valve body further includes a bottom slit extending from the bottom opening thereby enabling the radial expansion of the bottom opening when the valve housing is under high pressure. As a result of such expansion, the flow rate of the aerosol product during pressure filling can be substantially increased. Nevertheless, additional product filling paths achieved in both of the aforementioned examples require the deformation of delicate structural components, which may increases the production cost and decrease the robustness and reliability of the valve assembly.
Valve assemblies that use a guiding sleeve to block/unblock openings on the valve body in order to regulate the flow paths during product and/or propellant filling are also known in the art. For example, a known dual-chamber aerosol package includes an outer container, an inner container disposed in the outer container and a multi-functional dispensing valve. The dispensing valve includes a valve body, a valve stem inserted through the top opening of the valve body, and a guide sleeve slidably disposed within the valve body. The valve body further includes a bottom filling opening and a transverse side dispensing opening, wherein the bottom and side openings are in communication with the inner and outer containers, respectively. During a filling process, the guide sleeve blocks the dispensing opening and allows pressurized gas to be filled into the inner container through the bottom opening. At the end of the filling process, the guide sleeve is advanced to block the bottom opening while simultaneously unblocking the side dispensing opening, through which the product is dispensed. However, rather than increasing the flow rate during product filling and retaining regular flow rate during product dispensing, the guiding sleeve simply functions to regulate the direction of flow paths into the corresponding product and propellant chambers.
Hence, there is a need for a valve assembly for use in a pressurized dispenser to modulate the flow rate during product filling and dispensing. Moreover, there is a need for a valve assembly for use in a pressurized dispenser that provides increased product filling rate while retaining regular product dispensing rate. Further, there is a need for a flow-modulating valve member that is durable, robust, and economical to manufacture.